diff --git a/src/corelib/io/qfilesystemengine_win.cpp b/src/corelib/io/qfilesystemengine_win.cpp
index 60285cfea8..eeec5236e2 100644
--- a/src/corelib/io/qfilesystemengine_win.cpp
+++ b/src/corelib/io/qfilesystemengine_win.cpp
@@ -593,6 +593,9 @@ QNativeFilePermissions::QNativeFilePermissions(std::optional<QFileDevice::Permis
     sa.bInheritHandle = FALSE;
 
     isNull = false;
+#else
+    Q_UNUSED(perms);
+    Q_UNUSED(isDir);
 #endif // QT_CONFIG(fslibs)
     ok = true;
 }